The present invention relates to a compound miter saw and, more particularly, to an improved system for positioning of the cuttinghead for producing beveled cuts.
The present invention is embodied in a compound miter saw or the like comprising a base having a lower surface for supporting the base on a work surface. A turntable is rotatably supported by the base, and a fence is disposed above the work table for supporting the orientation of a workpiece located on the base. A support is coupled to the turntable at a rear portion of the turntable.
The compound miter saw disclosed also includes a cuttinghead system for cutting the workpiece. The cuttinghead system comprises a pivoting system coupled to the support for pivoting a motor driven saw between a raised, rest position and a lowered, operational position.
The compound miter saw disclosed in U.S. Pat. No. 4,934,233 assigned to Emerson Electrical Co. provides a beveling mechanism which substantially comprises a first right circular cylinder formed into the support and a second right circular cylinder formed into the cuttinghead system. These two right circular cylinders face one another and have relatively limited surface areas which interface. The interfacing surface areas are held together with a biasing system that can be loosened for the purpose of pivoting the cuttinghead system to a desired position for a beveled cut and that can be tightened for securing the cuttinghead system at the selected bevel angle. However, the relatively small surface area between the two face to face ends of the right circular cylinders disclosed in U.S. Pat. No. 4,934,233 can affect the stability for the cuttinghead, particularly when subjected to wear over continued use.
In contrast, the present compound miter saw beveling system provides a surface area having a conically configured interface which, even when subjected to wear, remains extremely stable during beveling adjustments of the cuttinghead and during use of the cuttinghead in locked positions.
The present beveling system comprises a male conical taper structure having an outer surface defining a cone-shaped member, the cone-shaped member being coupled to the support The beveling system further comprises a female conical taper structure defining a cavity having a conically-shaped inner wall, the conically-shaped inner wall having a configuration substantially matching the outer surface of the cone-shaped member. The female conical taper structure is coupled to the cuttinghead system.
The present beveling system further comprises a biasing system for permitting a user to adjustably bias the conically-shaped inner wall of the female conical taper structure onto the outer surface of the cone-shaped member. The biasing system permits selectively loosening the bias in order to enable the conically-shaped inner wall to rotate on the outer surface of the cone-shaped member, and therefore, enable the user to adjust the bevel of the cuttinghead system. The biasing system further permits selectively tightening the bias so that the user can lock the bevel of the cuttinghead system in a preferred position.